/*
* @param _funcType Style of the top line that generated
* @param _res Size of mapunits for one linear segment
* */
public PolygonActor(World _world, Vector2 _position, uint _seed, FunctionType _funcType, int _res = 5)
: base(_world, _position)
{
int lineCount = (int)Constants.worldSizeX / _res;
//make sure to have an even number
if (lineCount % 2 != 0) lineCount++;
Vec2[] verts = new Vec2[(int)lineCount + 1 + 4];
vertexBuffer = new VertexArray(PrimitiveType.LinesStrip);
Vector2 posScreen = _position.toScreenCoord();
//repeatable random sequenze
Rand rnd = new Rand(_seed);
//start and end have even ground
verts[0] = new Vec2(0, 6);
verts[1] = new Vec2(_res, 6);
verts[2] = new Vec2(_res + _res, 6);
verts[lineCount - 2] = new Vec2(_res * (lineCount - 2), 6);
verts[lineCount-1] = new Vec2(_res * (lineCount-1), 6);
verts[lineCount] = new Vec2(_res * lineCount, 6);
vertexBuffer.Append(new Vertex(((Vector2)verts[0] + _position).toScreenCoord()));
//create the function
if (_funcType == FunctionType.Simple)
{
for (int i = 2; i <= lineCount; ++i)
{
//Vector2 pos = new Vec2(i * 5, 10 + Rand.IntValue(10));
Vector2 pos = new Vec2(i * _res, System.Math.Max((verts[i - 1].Y + (int)rnd.next(6) - 3), 0));
verts[i] = pos;
}
}
else if(_funcType == FunctionType.GradientNoise)
{
for (int i = 2; i < lineCount-3;)
{
int nextGrad = i + 4;
if (nextGrad < lineCount - 2)
{
verts[nextGrad] = new Vec2(nextGrad * _res, rnd.next((int)maxHeight));
}
else nextGrad = lineCount - 2;
//interpolate between
float relativeA = verts[i].Y / maxHeight;
float relativeB = verts[nextGrad].Y / maxHeight;
for (int c = i + 1; c < nextGrad; ++c)
{
verts[c] = new Vec2(c * _res, maxHeight * interpolateCos(relativeA, relativeB, (float)(c - i) / 4));
}
i = nextGrad;
}
}
Array.Resize<Body>(ref triangleBodys, lineCount);
PolygonDef triangleDef = new PolygonDef();
triangleDef.Density = 0.0f;
triangleDef.Friction = 1.0f;
triangleDef.VertexCount = 3;
BodyDef bodydef = new BodyDef();
bodydef.Position = _position;
bodydef.Angle = 0.0f;
//convert to triangles
for (int i = 0; i < lineCount; ++i)
{
//always 3 points of the function form a triangle
triangleDef.Vertices[0] = verts[i];
triangleDef.Vertices[1] = verts[i] - new Vec2(0.0f, 50.0f);
triangleDef.Vertices[2] = verts[i + 1];//.Y < verts[i+1].Y ? verts[i] : verts[i + 1]
triangleBodys[i] = _world.CreateBody(bodydef);
triangleBodys[i].CreateShape(triangleDef);
vertexBuffer.Append(new Vertex(((Vector2)verts[i+1] + _position).toScreenCoord()));
}
}